This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
The subject matter disclosed herein relates generally to methods for separating and purifying biomolecules, and more specifically, to methods of liquid-liquid extraction isolation of polypeptides using aptamer-polymer conjugates.
A number of currently approved biopharmaceuticals are polypeptides (e.g., antibodies). Biopharmaceutical synthesis in production reactors (e.g. cell-based fermentation) is typically followed by downstream processing and purification to remove contaminants that are unwanted in the formulated biopharmaceutical. Contaminants may include but are not limited to host cell proteins, host cell DNA, intact cells or cell debris, endotoxins (in the case of bacterial production systems), viruses (in the case of mammalian production systems), misfolded proteins and aggregates, and components that leach from chromatographic media. Examples of purification techniques to separate a target polypeptide product from contaminants include centrifugation, filtration, and column-based chromatography. These techniques may include difficult process steps that lead to greater opportunities for system breakdown. There exists a need for improvement in purification, ideally selective-purification, using methods with simpler process steps. Also, it is desirable to affinity-purify a product, or selectively remove a contaminant, under high flow capacities, such as what might be experienced in continuous purification processes.